I bought a 13 tooth for my quad a while ago, it seemed to help with climing dunes and such, I can hit 5th gear no problem now. before I had a hard time using 5th. I've been seeing that some guys are going with 15 tooth? I would definatly be able to use 1st more often but what about 5th? are they going bigger in the rear also? what kinds of ratio's do you use and how's it work for you?